Mode
The term mode, in modern music theory, is usually used to refer to the rotations of a scale, that is, versions of the scale starting on each of its notes. An abstract scale pattern is usually mode-agnostic, without a specified root note, although one is usually chosen as the 'default' for notational purposes (e.g. LLsLLLs - each L represents a large step and each s represents a small step). For example, modes of LssLs include sLssL, LsLss, and the specific mode LssLs itself.
Modes are mostly used in the context of tonal or modal music, i.e. as opposed to atonal music, since their definition implies a tonic.
Examples
The diatonic scale has seven different modes. The following table shows the modes of the diatonic scale built on the white keys (C-D-E-F-G-A-B-C) and in the key of D. The modes can be sorted according to their tonic (sort by note names (white keys)) or their position in the circle of fifths (sort by step pattern)
| Name | Step pattern | Note names
(white keys) |
Note names
(in D) |
|---|---|---|---|
| Ionian (major) | LLsLLLs | C D E F G A B (C) | D E F♯ G A B C♯ (D) |
| Dorian | LsLLLsL | D E F G A B C (D) | D E F G A B C (D) |
| Phrygian | sLLLsLL | E F G A B C D (E) | D E♭ F G A B♭ C (D) |
| Lydian | LLLsLLs | F G A B C D E (F) | D E F♯ G♯ A B C♯ (D) |
| Mixolydian | LLsLLsL | G A B C D E F (G) | D E F♯ G A B C (D) |
| Aeolian (natural minor) | LsLLsLL | A B C D E F G (A) | D E F G A B♭ C (D) |
| Locrian | sLLsLLL | B C D E F G A (B) | D E♭ F G A♭ B♭ C (D) |
Properties
A scale has as many modes as the number of tones that it contains within a period. For example:
- The diatonic scale has 7 different modes, because it has 7 tones per period of 1 octave, and 7 possible keys as well;
- The octatonic diminished scale only has 2 different modes, because it has 2 tones per period of 1/4 octave, but it has 8 possible keys, since any of the 8 pitch classes of the scale can be chosen as the tonic.
Inversions
Inversions or homonyms are to chords what modes are to scales, and they are constructed essentially by treating a chord as a scale, and taking its modes. For example, the major triad, [1/1 5/4 3/2], has inversions [1/1 6/5 8/5] and [1/1 4/3 5/3].
